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Bernie -
I wholeheartedly concur. While high-pressure water will force SOME of the
CsCl into the pores in concrete and other materials, it WILL wash most (probably
90 - 95%, maybe more) of the CsCl somewhere ... you just have to be sure you
know where the runoff water is going, lest you create a bigger problem.
By the way, I received a private e-mail indicating that the values I gave
for relocation / return are changing. The draft Federal Radiological Monitoring
and Assessment Center (FRMAC) Assessment Manual, currently at DOE for review,
contains the following guidance levels for relocation and return:
1YR 45 uCi/m2
2YR 11 uCi//m2 50YR 3.7 uCi/m2 Jim Hardeman
Jim_Hardeman@dnr.state.ga.us
>>> BERNARD L COHEN <blc+@pitt.edu> 3/3/2003 9:41:48 >>> My humble opinion is to use the hoses as effectively as possible and as soon as possible -- diffusion into materials and even surface binding take time, so get rid of as much as is easy as fast as practical. Then, there is time to evaluate the problem and make decisions about further measures. But what we can do now is show that the calculated number of deaths advertised by the alarmists are complete nonsense, since they ignore even the easy clean-up, and assure the public that there is nothing major to fear. This is a message we should be trying to get out loud and clear and immediately. If we do get it out, the terrorists will have little reason to use a dirty bomb. I thought the analogy with salt used on roads would be useful in this endeavor. We should be writing papers on debunking the alarmists, and info on effectiveness of clean-up would be useful for this purpose. Bernard L. Cohen Physics Dept. University of Pittsburgh Pittsburgh, PA 15260 Tel: (412)624-9245 Fax: (412)624-9163 e-mail: blc@pitt.edu On Fri, 28 Feb 2003, Nardi, A. Joseph wrote: > This is really an issue of "How clean is clean enough". When > decommissioning a licensed facility we are required to take more effort to > chase "the last atom" because of the exposure scenarios that are associated > with the development of cleanup criteria. Such decommissioning scenarios > should not be considered applicable to the cleanup associated with an act of > terrorism particularly in an outdoor environment. It seems to me that one > of the considerations that should be thought out now is what would be the > appropriate cleanup criteria to be applied in the event of such an act of > terrorism. Otherwise we are going to end up with the default criteria. The > elements that would be required to establish appropriate criteria might be > as follows: > > * Establish a rational dose criteria to be used in these scenarios. > This might be done on a time dependent basis such as the first five years, > the second 10 years, etc. > * Define a realistic scenario for the dose calculation based on > different dirty bomb scenarios. > * Establish a model that is based on realistic model parameters, not > using the general approach for decommissioning models where the parameters > are the 90th percentile or other levels of conservatism. > * Use the above to establish reasonably protective cleanup criteria > that can be used in such an event before the act rather than trying to > develop the criteria in the "heat of the moment". > > Just my humble opinion > > > A. Joseph Nardi, Supervisory Engineer > Westinghouse Electric Company > P. O. Box 355 > Pittsburgh, PA 15230 > Telephone: 412-374-4652 > FAX Number: 412-374-3357 > email: nardiaj@westinghouse.com > > > John Andrews wrote: > > > I cleaned up an old spill of Cs-137 once. The material had been cleaned > > up years earlier, but residual material remained on some of the > > concrete. It had penetrated into the concrete up to one inch in > > discrete spots. This indicated to me that actual grains of the spilled > > source material remained on the concrete and the cesium was sorbed by > > whatever reaction into the concrete. There was low level general > > contamination just above backround in adjacent areas indicating > > migration from the hot spots. Effective cleaning included jackhammering > > or intense needle-gun decon of the spots and scabbling the general areas > > to 1/2 inch. > > > > I would expect the same from any Cs-137 spill. > > > > John Andrews > > Knoxville, Tennessee > > > > ************************************************************************ > > You are currently subscribed to the Radsafe mailing list. To unsubscribe, > > send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe > > radsafe" (no quote marks) in the body of the e-mail, with no subject line. > > You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/ > > > > > ************************************************************************ You are currently subscribed to the Radsafe mailing list. To unsubscribe, send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe radsafe" (no quote marks) in the body of the e-mail, with no subject line. You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/ |